Generally a good talk and a good defense, but I didn't quite appreciate his new definitions of "State" and "Concurrency". And did he really compare a full oper

Generally a good talk and a good defense, but I didn't quite appreciate his new definitions of "State" and "Concurrency". And did he really compare a full operating system to Facebook's web apps in terms of complexity? If that's true, there has to be a lot of accidental complexity in FB.